1
|
Song H, Mah B, Sun Y, Aloysius N, Bai Y, Zhang L. Development of spontaneous recurrent seizures accompanied with increased rates of interictal spikes and decreased hippocampal delta and theta activities following extended kindling in mice. Exp Neurol 2024; 379:114860. [PMID: 38876195 DOI: 10.1016/j.expneurol.2024.114860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 05/30/2024] [Accepted: 06/09/2024] [Indexed: 06/16/2024]
Abstract
Interictal epileptiform discharges refer to aberrant brain electrographic signals between seizures and feature intermittent interictal spikes (ISs), sharp waves, and/or abnormal rhythms. Recognition of these epileptiform activities by electroencephalographic (EEG) examinations greatly aids epilepsy diagnosis and localization of the seizure onset zone. ISs are a major form of interictal epileptiform discharges recognized in animal models of epilepsy. Progressive changes in IS waveforms, IS rates, and/or associated fast ripple oscillations have been shown to precede the development of spontaneous recurrent seizures (SRS) in various animal models. IS expressions in the kindling model of epilepsy have been demonstrated but IS changes during the course of SRS development in extended kindled animals remain to be detailed. We hence addressed this issue using a mouse model of kindling-induced SRS. Adult C57 black mice received twice daily hippocampal stimulations until SRS occurrence, with 24-h EEG monitoring performed following 50, 80, and ≥ 100 stimulations and after observation of SRS. In the stimulated hippocampus, increases in spontaneous ISs rates, but not in IS waveforms nor IS-associated fast ripples, along with decreased frequencies of hippocampal delta and theta rhythms, were observed before SRS onset. Comparable increases in IS rates were further observed in the unstimulated hippocampus, piriform cortex, and entorhinal cortex, but not in the unstimulated parietal cortex and dorsomedial thalamus. These data provide original evidence suggesting that increases in hippocampal IS rates, together with reductions in hippocampal delta and theta rhythms are closely associated with development of SRS in a rodent kindling model.
Collapse
Affiliation(s)
- Hongmei Song
- Department of Neurosurgery, the First Hospital of Jilin University, China; Krembil Research Institute, University Health Network, Canada.
| | - Bryan Mah
- Krembil Research Institute, University Health Network, Canada
| | - Yuqing Sun
- Krembil Research Institute, University Health Network, Canada
| | - Nancy Aloysius
- Krembil Research Institute, University Health Network, Canada
| | - Yang Bai
- Department of Neuro-Oncology, the First Hospital of Jilin University, China.
| | - Liang Zhang
- Krembil Research Institute, University Health Network, Canada; Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
2
|
Cole ER, Grogan DP, Laxpati NG, Fernandez AM, Skelton HM, Isbaine F, Gutekunst CA, Gross RE. Evidence supporting deep brain stimulation of the medial septum in the treatment of temporal lobe epilepsy. Epilepsia 2022; 63:2192-2213. [PMID: 35698897 DOI: 10.1111/epi.17326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 12/28/2022]
Abstract
Electrical brain stimulation has become an essential treatment option for more than one third of epilepsy patients who are resistant to pharmacological therapy and are not candidates for surgical resection. However, currently approved stimulation paradigms achieve only moderate success, on average providing approximately 75% reduction in seizure frequency and extended periods of seizure freedom in nearly 20% of patients. Outcomes from electrical stimulation may be improved through the identification of novel anatomical targets, particularly those with significant anatomical and functional connectivity to the epileptogenic zone. Multiple studies have investigated the medial septal nucleus (i.e., medial septum) as such a target for the treatment of mesial temporal lobe epilepsy. The medial septum is a small midline nucleus that provides a critical functional role in modulating the hippocampal theta rhythm, a 4-7-Hz electrophysiological oscillation mechanistically associated with memory and higher order cognition in both rodents and humans. Elevated theta oscillations are thought to represent a seizure-resistant network activity state, suggesting that electrical neuromodulation of the medial septum and restoration of theta-rhythmic physiology may not only reduce seizure frequency, but also restore cognitive comorbidities associated with mesial temporal lobe epilepsy. Here, we review the anatomical and physiological function of the septohippocampal network, evidence for seizure-resistant effects of the theta rhythm, and the results of stimulation experiments across both rodent and human studies, to argue that deep brain stimulation of the medial septum holds potential to provide an effective neuromodulation treatment for mesial temporal lobe epilepsy. We conclude by discussing the considerations necessary for further evaluating this treatment paradigm with a clinical trial.
Collapse
Affiliation(s)
- Eric R Cole
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | | | - Nealen G Laxpati
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Alejandra M Fernandez
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Henry M Skelton
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Faical Isbaine
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Claire-Anne Gutekunst
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Robert E Gross
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA.,Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
| |
Collapse
|
3
|
Fu X, Wang Y, Belkacem AN, Cao Y, Cheng H, Zhao X, Chen S, Chen C. Interictal Spike and Loss of Hippocampal Theta Rhythm Recorded by Deep Brain Electrodes during Epileptogenesis. SENSORS 2022; 22:s22031114. [PMID: 35161860 PMCID: PMC8838088 DOI: 10.3390/s22031114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/25/2022] [Accepted: 01/28/2022] [Indexed: 02/01/2023]
Abstract
Epileptogenesis is the gradual dynamic process that progressively led to epilepsy, going through the latent stage to the chronic stage. During epileptogenesis, how the abnormal discharges make theta rhythm loss in the deep brain remains not clear. In this paper, a loss of theta rhythm was estimated based on time–frequency power using the longitudinal electroencephalography (EEG), recorded by deep brain electrodes (e.g., the intracortical microelectrodes such as stereo-EEG electrodes) with monitored epileptic spikes in a rat from the first region in the hippocampal circuit. Deep-brain EEG was collected from the period between adjacent sporadic interictal spikes (lasting 3.56 s—35.38 s) to the recovery period without spikes by videos while the rats were performing exploration. We found that loss of theta rhythm became more serious during the period between adjacent interictal spikes than during the recovery period without spike, and during epileptogenesis, more loss was observed at the acute stage than the chronic stage. We concluded that the emergence of the interictal spike was the direct cause of loss of theta rhythm, and the inhibitory effect of the interictal spike on ongoing theta rhythm was persistent as well as time dependent during epileptogenesis. With the help of the intracortical microelectrodes, this study provides a temporary proof of interictal spikes to produce ongoing theta rhythm loss, suggesting that the interictal spikes could correlate with the epileptogenesis process, display a time-dependent feature, and might be a potential biomarker to evaluate the deficits in theta-related memory in the brain.
Collapse
Affiliation(s)
- Xiaoxuan Fu
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China; (X.F.); (Y.W.); (Y.C.); (H.C.); (X.Z.)
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, China
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29464, USA
| | - Youhua Wang
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China; (X.F.); (Y.W.); (Y.C.); (H.C.); (X.Z.)
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, China
| | - Abdelkader Nasreddine Belkacem
- Department of Computer and Network Engineering, College of Information Technology, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates;
| | - Yingxin Cao
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China; (X.F.); (Y.W.); (Y.C.); (H.C.); (X.Z.)
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, China
| | - Hao Cheng
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China; (X.F.); (Y.W.); (Y.C.); (H.C.); (X.Z.)
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, China
| | - Xiaohu Zhao
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China; (X.F.); (Y.W.); (Y.C.); (H.C.); (X.Z.)
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, China
| | - Shenghua Chen
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China; (X.F.); (Y.W.); (Y.C.); (H.C.); (X.Z.)
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, China
- Correspondence: (S.C.); (C.C.)
| | - Chao Chen
- Key Laboratory of Complex System Control Theory and Application, Tianjin University of Technology, Tianjin 300384, China
- Correspondence: (S.C.); (C.C.)
| |
Collapse
|
4
|
Abstract
SUMMARY Although interictal spikes (IISs) are a well-established EEG biomarker for epilepsy, whether they are also a biomarker of cognitive deficits is unclear. Interictal spikes are dynamic events consisting of a synchronous discharge of neurons producing high frequency oscillations and a succession of action potentials which disrupt the ongoing neural activity. There are robust data showing that IISs result in transitory cognitive impairment with the type of deficit specific to the cognitive task and anatomic location of the IIS. Interictal spike, particularly if frequent and widespread, can impair cognitive abilities, through interference with waking learning and memory and memory consolidation during sleep. Interictal spikes seem to be particularly concerning in the developing brain where animal data suggest that IISs can lead to adverse cognitive effects even after the disappearance of the spikes. Whether a similar phenomenon occurs in human beings is unclear. Thus, although IISs are a clear biomarker of transitory cognitive impairment, currently, they lack sensitivity and specificity as a biomarker for enduring cognitive impairment.
Collapse
Affiliation(s)
- Gregory L Holmes
- Department of Neurological Sciences Larner College of Medicine at the University of Vermont, Burlington, Vermont, U.S.A
| |
Collapse
|
5
|
Righes Marafiga J, Vendramin Pasquetti M, Calcagnotto ME. In vitro Oscillation Patterns Throughout the Hippocampal Formation in a Rodent Model of Epilepsy. Neuroscience 2021; 479:1-21. [PMID: 34710537 DOI: 10.1016/j.neuroscience.2021.10.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 11/29/2022]
Abstract
Specific oscillatory patterns are considered biomarkers of pathological neuronal network in brain diseases, such as epilepsy. However, the dynamics of underlying oscillations during the epileptogenesis throughout the hippocampal formation in the temporal lobe epilepsy is not clear. Here, we characterized in vitro oscillatory patterns within the hippocampal formation of epileptic rats, under 4-aminopyridine (4-AP)-induced hyperexcitability and during the spontaneous network activity, at two periods of epileptogenesis. First, at the beginning of epileptic chronic phase, 30 days post-pilocarpine-induced Status Epilepticus (SE). Second, at the established epilepsy, 60 days post-SE. The 4-AP-bathed slices from epileptic rats had increased susceptibility to ictogenesis in CA1 at 30 days post-SE, and in entorhinal cortex and dentate gyrus at 60 days post-SE. Higher power and phase coherence were detected mainly for gamma and/or high frequency oscillations (HFOs), in a region- and stage-specific manner. Interestingly, under spontaneous network activity, even without 4-AP-induced hyperexcitability, slices from epileptic animals already exhibited higher power of gamma and HFOs in different areas of hippocampal formation at both periods of epileptogenesis, and higher phase coherence in fast ripples at 60 days post-SE. These findings reinforce the critical role of gamma and HFOs in each one of the hippocampal formation areas during ongoing neuropathological processes, tuning the neuronal network to epilepsy.
Collapse
Affiliation(s)
- Joseane Righes Marafiga
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory (NNNESP Lab.), Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, RS, Brazil; Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, RS, Brazil
| | - Mayara Vendramin Pasquetti
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory (NNNESP Lab.), Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, RS, Brazil; Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, RS, Brazil
| | - Maria Elisa Calcagnotto
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory (NNNESP Lab.), Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, RS, Brazil; Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, RS, Brazil.
| |
Collapse
|
6
|
A Simulation on Relation between Power Distribution of Low-Frequency Field Potentials and Conducting Direction of Rhythm Generator Flowing through 3D Asymmetrical Brain Tissue. Symmetry (Basel) 2021. [DOI: 10.3390/sym13050900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Although the power of low-frequency oscillatory field potentials (FP) has been extensively applied previously, few studies have investigated the influence of conducting direction of deep-brain rhythm generator on the power distribution of low-frequency oscillatory FPs on the head surface. To address this issue, a simulation was designed based on the principle of electroencephalogram (EEG) generation of equivalent dipole current in deep brain, where a single oscillatory dipole current represented the rhythm generator, the dipole moment for the rhythm generator’s conducting direction (which was orthogonal and rotating every 30 degrees and at pointing to or parallel to the frontal lobe surface) and the (an)isotropic conduction medium for the 3D (a)symmetrical brain tissue. Both the power above average (significant power value, SP value) and its space (SP area) of low-frequency oscillatory FPs were employed to respectively evaluate the strength and the space of the influence. The computation was conducted using the finite element method (FEM) and Hilbert transform. The finding was that either the SP value or the SP area could be reduced or extended, depending on the conducting direction of deep-brain rhythm generator flowing in the (an)isotropic medium, suggesting that the 3D (a)symmetrical brain tissue could decay or strengthen the spatial spread of a rhythm generator conducting in a different direction.
Collapse
|
7
|
Chauvière L. Potential causes of cognitive alterations in temporal lobe epilepsy. Behav Brain Res 2020; 378:112310. [DOI: 10.1016/j.bbr.2019.112310] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/15/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022]
|
8
|
Chauvière L. Update on temporal lobe‐dependent information processing, in health and disease. Eur J Neurosci 2019; 51:2159-2204. [DOI: 10.1111/ejn.14594] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/06/2019] [Accepted: 09/27/2019] [Indexed: 01/29/2023]
Affiliation(s)
- Laëtitia Chauvière
- INSERM U1266 Institut de Psychiatrie et de Neurosciences de Paris (IPNP) Paris France
| |
Collapse
|
9
|
Jiang G, Pu T, Li Z, Zhang X, Zhou R, Cao X, Yu J, Wang X. Lithium affects rat hippocampal electrophysiology and epileptic seizures in a dose dependent manner. Epilepsy Res 2018; 146:112-120. [DOI: 10.1016/j.eplepsyres.2018.07.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/20/2018] [Accepted: 07/27/2018] [Indexed: 12/14/2022]
|
10
|
Fu X, Wang Y, Ge M, Wang D, Gao R, Wang L, Guo J, Liu H. Negative effects of interictal spikes on theta rhythm in human temporal lobe epilepsy. Epilepsy Behav 2018; 87:207-212. [PMID: 30115601 PMCID: PMC6544467 DOI: 10.1016/j.yebeh.2018.07.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 03/19/2018] [Accepted: 07/20/2018] [Indexed: 10/28/2022]
Abstract
Interictal spike is a biomarker of epilepsy that can occur frequently between seizures. Its potential effects on brain oscillations, especially on theta rhythm (4-8 Hz) that is related to a variety of cognitive processes, remain controversial. Using local field potentials recorded from patients with temporal lobe epilepsy (TLE), we investigated here the impact of spikes on theta rhythm immediately after spikes and during the prolonged periods (lasting 4-36 s) between adjacent spikes. Local field potentials (LFPs) were recorded in different epileptogenic areas including the anterior hippocampus (aH) and the entorhinal cortex (EC) as well as in the extended propagation pathway. We found that interictal spikes had a significant inhibitory effect on theta rhythm. Power of theta rhythm was reduced immediately after spikes, and the inhibitory effect on theta rhythm might sustain during the prolonged between-spike periods. The inhibitory effect was more severe when the epileptogenic areas involved both the aH and EC compared to that involved only a single structure. These observations suggest that interictal spikes have a significant negative impact on theta rhythm and may thus play a role in theta-related cognition changes in patients with TLE.
Collapse
Affiliation(s)
- Xiaoxuan Fu
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, 369#, Tianjin 300130, China
| | - Youhua Wang
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, 369#, Tianjin 300130, China
| | - Manling Ge
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, 369#, Tianjin 300130, China.
| | - Danhong Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Rongguang Gao
- Department of Nuclear Medicine, Fuzhou General Hospital, No. 156, Second West Ring Road, Fuzhou 350025, China
| | - Long Wang
- Liaoyuan Hospital of Traditional Chinese Medicine, Liaoyuan 136200, China
| | - Jundan Guo
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, 369#, Tianjin 300130, China
| | - Hesheng Liu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA; Institute for Research and Medical Consultations, Imam Abdulahman Bin Faisal University, Dammam, Saudi Arabia.
| |
Collapse
|
11
|
Acute Increases in Protein O-GlcNAcylation Dampen Epileptiform Activity in Hippocampus. J Neurosci 2017; 37:8207-8215. [PMID: 28760863 DOI: 10.1523/jneurosci.0173-16.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/02/2017] [Accepted: 07/08/2017] [Indexed: 11/21/2022] Open
Abstract
O-GlcNAcylation is a ubiquitous and dynamic post-translational modification involving the O-linkage of β-N-acetylglucosamine to serine/threonine residues of membrane, cytosolic, and nuclear proteins. This modification is similar to phosphorylation and regarded as a key regulator of cell survival and homeostasis. Previous studies have shown that phosphorylation of serine residues on synaptic proteins is a major regulator of synaptic strength and long-term plasticity, suggesting that O-GlcNAcylation of synaptic proteins is likely as important as phosphorylation; however, few studies have investigated its role in synaptic efficacy. We recently demonstrated that acutely increasing O-GlcNAcylation induces a novel form of LTD at CA3-CA1 synapses, O-GlcNAc LTD. Here, using hippocampal slices from young adult male rats and mice, we report that epileptiform activity at CA3-CA1 synapses, generated by GABAAR inhibition, is significantly attenuated when protein O-GlcNAcylation is pharmacologically increased. This dampening effect is lost in slices from GluA2 KO mice, indicating a requirement of GluA2-containing AMPARs, similar to expression of O-GlcNAc LTD. Furthermore, we find that increasing O-GlcNAcylation decreases spontaneous CA3 pyramidal cell activity under basal and hyperexcitable conditions. This dampening effect was also observed on cortical hyperexcitability during in vivo EEG recordings in awake mice where the effects of the proconvulsant pentylenetetrazole are attenuated by acutely increasing O-GlcNAcylation. Collectively, these data demonstrate that the post-translational modification, O-GlcNAcylation, is a novel mechanism by which neuronal and synaptic excitability can be regulated, and suggest the possibility that increasing O-GlcNAcylation could be a novel therapeutic target to treat seizure disorders and epilepsy.SIGNIFICANCE STATEMENT We recently reported that an acute pharmacological increase in protein O-GlcNAcylation induces a novel form of long-term synaptic depression at hippocampal CA3-CA1 synapses (O-GlcNAc LTD). This synaptic dampening effect on glutamatergic networks suggests that increasing O-GlcNAcylation will depress pathological hyperexcitability. Using in vitro and in vivo models of epileptiform activity, we show that acutely increasing O-GlcNAc levels can significantly attenuate ongoing epileptiform activity and prophylactically dampen subsequent seizure activity. Together, our findings support the conclusion that protein O-GlcNAcylation is a regulator of neuronal excitability, and it represents a promising target for further research on seizure disorder therapeutics.
Collapse
|
12
|
Ge M, Guo J, Xing Y, Feng Z, Lu W, Ma X, Geng Y, Zhang X. Transient reduction in theta power caused by interictal spikes in human temporal lobe epilepsy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2017:4256-4259. [PMID: 29060837 DOI: 10.1109/embc.2017.8037796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The inhibitory impacts of spikes on LFP theta rhythms(4-8Hz) are investigated around sporadic spikes(SSs) based on intracerebral EEG of 4 REM sleep patients with temporal lobe epilepsy(TLE) under the pre-surgical monitoring. Sequential interictal spikes in both genesis area and extended propagation pathway are collected, that, SSs genesis only in anterior hippocampus(aH)(possible propagation pathway in Entorhinal cortex(EC)), only in EC(possible propagation pathway in aH), and in both aH and EC synchronously. Instantaneous theta power was estimated by using Gabor wavelet transform, and theta power level was estimated by averaged over time and frequency before SSs(350ms pre-spike) and after SSs(350ms post-spike). The inhibitory effect around spikes was evaluated by the ratio of theta power level difference between pre-spike and post-spike to pre-spike theta power level. The findings were that theta power level was reduced across SSs, and the effects were more sever in the case of SSs in both aH and EC synchronously than either SSs only in EC or SSs only in aH. It is concluded that interictal spikes impair LFP theta rhythms transiently and directly. The work suggests that the reduction of theta power after the interictal spike might be an evaluation indicator of damage of epilepsy to human cognitive rhythms.
Collapse
|
13
|
Ge M, Fu X, Zhang J, Chen S, Chen Y, Gao R, Zhang H. The influences of tissue anisotropy and source activity on power and phase stability of low-frequency EEG rhythms: a mathematical observation of the forward problem model. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/3/035019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
14
|
Clemens B, Puskás S, Spisák T, Lajtos I, Opposits G, Besenyei M, Hollódy K, Fogarasi A, Kovács NZ, Fekete I, Emri M. Increased resting-state EEG functional connectivity in benign childhood epilepsy with centro-temporal spikes. Seizure 2016; 35:50-5. [PMID: 26794010 DOI: 10.1016/j.seizure.2016.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 11/15/2015] [Accepted: 01/03/2016] [Indexed: 01/23/2023] Open
Abstract
PURPOSE To explore intrahemispheric, cortico-cortical EEG functional connectivity (EEGfC) in benign childhood epilepsy with rolandic spikes (BECTS). METHODS 21-channel EEG was recorded in 17 non-medicated BECTS children and 19 healthy controls. 180s of spike- and artifact-free activity was selected for EEGfC analysis. Correlation of Low Resolution Electromagnetic Tomography- (LORETA-) defined current source density time series were computed between two cortical areas (region of interest, ROI). Analyses were based on broad-band EEGfC results. Groups were compared by statistical parametric network (SPN) method. Statistically significant differences between group EEGfC values were emphasized at p<0.05 corrected for multiple comparison by local false discovery rate (FDR). RESULTS (1) Bilaterally increased beta EEGfC occurred in the BECTS group as compared to the controls. Greatest beta abnormality emerged between frontal and frontal, as well as frontal and temporal ROIs. (2) Locally increased EEGfC emerged in all frequency bands in the right parietal area. CONCLUSIONS Areas of increased EEGfC topographically correspond to cortical areas that, based on relevant literature, are related to speech and attention deficit in BECTS children.
Collapse
Affiliation(s)
- Béla Clemens
- Kenézy Gyula Hospital, Department of Neurology, Debrecen, Hungary
| | - Szilvia Puskás
- University of Debrecen, Medical Center, Department of Neurology, Debrecen, Hungary.
| | - Tamás Spisák
- University of Debrecen, Institute of Nuclear Medicine, Debrecen, Hungary
| | - Imre Lajtos
- University of Debrecen, Institute of Nuclear Medicine, Debrecen, Hungary
| | - Gábor Opposits
- University of Debrecen, Institute of Nuclear Medicine, Debrecen, Hungary
| | - Mónika Besenyei
- University of Debrecen, Medical Center, Department of Pediatrics, Debrecen, Hungary
| | | | - András Fogarasi
- Epilepsy Center, Bethesda Children's Hospital, Budapest, Hungary
| | | | - István Fekete
- University of Debrecen, Medical Center, Department of Neurology, Debrecen, Hungary
| | - Miklós Emri
- University of Debrecen, Institute of Nuclear Medicine, Debrecen, Hungary
| |
Collapse
|
15
|
Parrish RR, Buckingham SC, Mascia KL, Johnson JJ, Matyjasik MM, Lockhart RM, Lubin FD. Methionine increases BDNF DNA methylation and improves memory in epilepsy. Ann Clin Transl Neurol 2015; 2:401-16. [PMID: 25909085 PMCID: PMC4402085 DOI: 10.1002/acn3.183] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 01/20/2015] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) patients exhibit signs of memory impairments even when seizures are pharmacologically controlled. Surprisingly, the underlying molecular mechanisms involved in TLE-associated memory impairments remain elusive. Memory consolidation requires epigenetic transcriptional regulation of genes in the hippocampus; therefore, we aimed to determine how epigenetic DNA methylation mechanisms affect learning-induced transcription of memory-permissive genes in the epileptic hippocampus. METHODS Using the kainate rodent model of TLE and focusing on the brain-derived neurotrophic factor (Bdnf) gene as a candidate of DNA methylation-mediated transcription, we analyzed DNA methylation levels in epileptic rats following learning. After detection of aberrant DNA methylation at the Bdnf gene, we investigated functional effects of altered DNA methylation on hippocampus-dependent memory formation in our TLE rodent model. RESULTS We found that behaviorally driven BdnfDNA methylation was associated with hippocampus-dependent memory deficits. Bisulfite sequencing revealed that decreased BdnfDNA methylation levels strongly correlated with abnormally high levels of BdnfmRNA in the epileptic hippocampus during memory consolidation. Methyl supplementation via methionine (Met) increased BdnfDNA methylation and reduced BdnfmRNA levels in the epileptic hippocampus during memory consolidation. Met administration reduced interictal spike activity, increased theta rhythm power, and reversed memory deficits in epileptic animals. The rescue effect of Met treatment on learning-induced BdnfDNA methylation, Bdnf gene expression, and hippocampus-dependent memory, were attenuated by DNA methyltransferase blockade. INTERPRETATION Our findings suggest that manipulation of DNA methylation in the epileptic hippocampus should be considered as a viable treatment option to ameliorate memory impairments associated with TLE.
Collapse
Affiliation(s)
- R Ryley Parrish
- Department of Neurobiology, University of Alabama - Birmingham Birmingham, Alabama
| | - Susan C Buckingham
- Department of Neurobiology, University of Alabama - Birmingham Birmingham, Alabama
| | - Katherine L Mascia
- Department of Neurobiology, University of Alabama - Birmingham Birmingham, Alabama
| | - Jarvis J Johnson
- Department of Neurobiology, University of Alabama - Birmingham Birmingham, Alabama
| | | | - Roxanne M Lockhart
- Department of Neurobiology, University of Alabama - Birmingham Birmingham, Alabama
| | - Farah D Lubin
- Department of Neurobiology, University of Alabama - Birmingham Birmingham, Alabama
| |
Collapse
|
16
|
González MI, Grabenstatter HL, Cea-Del Rio CA, Cruz Del Angel Y, Carlsen J, Laoprasert RP, White AM, Huntsman MM, Brooks-Kayal A. Seizure-related regulation of GABAA receptors in spontaneously epileptic rats. Neurobiol Dis 2015; 77:246-56. [PMID: 25769812 DOI: 10.1016/j.nbd.2015.03.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 02/26/2015] [Accepted: 03/03/2015] [Indexed: 01/13/2023] Open
Abstract
In this study, we analyzed the impact that spontaneous seizures might have on the plasma membrane expression, composition and function of GABAA receptors (GABAARs). For this, the tissue of chronically epileptic rats was collected within 3h of seizure occurrence (≤3h group) or at least 24h after seizure occurrence (≥24h group). A retrospective analysis of seizure frequency revealed that selecting animals on the bases of seizure proximity also grouped animals in terms of overall seizure burden with a higher seizure burden observed in the ≤3h group. A biochemical analysis showed that although animals with more frequent/recent seizures (≤3h group) had similar levels of GABAAR at the plasma membrane they showed deficits in inhibitory neurotransmission. By contrast, the tissue obtained from animals experiencing infrequent seizures (≥24h group) had increased plasma membrane levels of GABAAR and showed no deficit in inhibitory function. Together, our findings offer an initial insight into the molecular changes that might help to explain how alterations in GABAAR function can be associated with differential seizure burden. Our findings also suggest that increased plasma membrane levels of GABAAR might act as a compensatory mechanism to more effectively maintain inhibitory function, repress hyperexcitability and reduce seizure burden. This study is an initial step towards a fuller characterization of the molecular events that trigger alterations in GABAergic neurotransmission during chronic epilepsy.
Collapse
Affiliation(s)
- Marco I González
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA.
| | - Heidi L Grabenstatter
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA
| | - Christian A Cea-Del Rio
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA
| | - Yasmin Cruz Del Angel
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA
| | - Jessica Carlsen
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA
| | - Rick P Laoprasert
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA
| | - Andrew M White
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA
| | - Molly M Huntsman
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA; Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA
| | - Amy Brooks-Kayal
- Department of Pediatrics, Division of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045 USA; Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Translational Epilepsy Research Program, University of Colorado Aurora CO 80045, USA; Children's Hospital Colorado, Aurora, CO 80045, USA
| |
Collapse
|
17
|
Valproate treatment normalizes EEG functional connectivity in successfully treated idiopathic generalized epilepsy patients. Epilepsy Res 2014; 108:1896-903. [PMID: 25454501 DOI: 10.1016/j.eplepsyres.2014.09.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/13/2014] [Accepted: 09/29/2014] [Indexed: 11/21/2022]
Abstract
AIM To investigate the effect of chronic VPA treatment of EEG functional connectivity in successfully treated idiopathic generalized epilepsy (IGE) patients. PATIENTS AND METHODS 19-channel waking, resting-state EEG records of 26 IGE patients were analyzed before treatment (IGE) and after the 90th day of treatment (VPA), in seizure-free condition. Three minutes of artifact-free EEG background activity (without epileptiform potentials) was analyzed for each patient in both conditions. A group of 26 age-matched healthy normative control persons (NC) was analyzed in the same way. All the EEG samples were processed to LORETA (Low Resolution Electromagnetic Tomography) to localize multiple distributed sources of EEG activity. Current source density time series were generated for 33 regions of interest (ROI) in each hemisphere for four frequency bands. Pearson correlation coefficients (R) were computed between all ROIs in each hemisphere, for four bands across the investigated samples. R values corresponded to intrahemispheric, cortico-cortical functional EEG connectivity (EEGfC). Group and condition differences were analyzed by statistical parametric network method. MAIN RESULTS p<0.05, corrected for multiple comparisons: (1) The untreated IGE group showed increased EEGfC in the delta and theta bands, and decreased EEGfC in the alpha band (as compared to the NC group); (2) VPA treatment normalized EEGfC in the delta, theta and alpha bands; and (3) degree of normalization depended on frequency band and cortical region. CONCLUSIONS VPA treatment normalizes EEGfC in IGE patients.
Collapse
|